A. Field of the Invention
The present invention refers to a method and a machine for the manufacture of syringes and, more particularly, to a method and a machine for the manufacturing the syringe glass bodies from vertically fed long glass tubes in a horizontally rotary forming machine including two forming sections.
B. Description of the Related Art
Typical glass syringes normally comprises a tubular syringe body including a finger flange and a tip for a needle, a steel needle having a flared end to be inserted by pressure at the tip of the syringe body, a stem having a gum plunger at its rear end and a top flat end, which is normally introduced into the tubular syringe body, to complete the syringe.
The syringe body has been normally produced at an horizontal forming machine typically used for producing glass ampoules, from a short glass tube having a length equivalent to a twice length of the syringe body, which is horizontally feed to the forming machine from a horizontally stacked glass tube hopper.
In said horizontal forming machine, each glass tube is horizontally fed from the tube hopper to an intermittent advancing rack leading the tubes through a plurality of forming stations including a plurality of burner nozzles and forming tools. The tip portion of the syringe body is firstly formed at a first end of the glass tube at a first machine section, then the glass tube is lifted, horizontally rotated and lowered to be feed to a second longitudinal machine section, to form a tip portion at the second end of the glass tube, and then the glass tube having a tip portion formed at each end thereof, is cutoff by its middle portion to be independently processed to form the finger flange of the syringe body.
Forming and feeding short, double sized, glass tubes, has been an inconvenient step in the manufacturing of syringe glass bodies. Furthermore, the production capacity of these machines is limited because of the length of the forming machine.
The forming cycle in these machines may take a considerable time and may require independent machines for the formation of the finger flange at each of the two syringe bodies obtained from a glass tube.
Consequently, it would be highly desirable to produce finished glass syringe bodies including the tip portion and the finger flange, in a single forming machine, in a single forming cycle, from long glass tubes to avoid the necessity of forming short, double sized, glass tubes.
There are known in the art some intermittently rotary type forming machines for producing glass ampoules and vials, from a plurality of vertical long glass tubes, as those disclosed in the U.S. Pat. No. 4,080,189 and U.S. Pat. No. 4,092,142 both of Dichter, and 4,330,317 of Vertova.
These rotary machines normally include a stationary machine frame and an intermittently rotary machine frame, mounted on the stationary machine frame, rotating to a plurality of forming stations; a plurality of continuously rotary chucks equally mounted on the stationary machine frame, rotary gripping the glass tubes; a plurality of burner nozzles equally and stationary mounted on the stationary machine frame at the forming stations, providing a flame jet for heating, softening, forming and fire finishing the glass tubes or products, and forming rollers for forming the mouth of a vial.
These rotary forming machines have the enormous advantage that produce the ampoules or vials, continuously, from long glass tubes in a single machine and in a single forming cycle.
Researching about the way in which glass syringes could be formed in a single continuous forming cycle, form long glass tubes, applicants have developed a method for the continuous manufacturing of syringe bodies in a single forming cycle, which can be carried out in a single intermittently rotary type forming machine, by properly tooling the machine and complementing it with another forming section in order to form a finished syringe body at a high production velocity.
The method for the manufacturing of syringe bodies from a plurality of glass tubes in an intermittently horizontally rotary machine including a first and a second intermittently horizontally rotary machine sections, in accordance with the present invention, comprising: vertically placing a plurality of glass tubes in a first machine section of the intermittently horizontally rotary machine, intermittently rotating to a plurality of forming stations, mounted on a central axis of a stationary machine frame; continuously rotary holding each tube by means of rotary gripping chucks equally and stationary mounted on the stationary machine frame; translating a tube to a plurality of forming stations by intermittently rotating the first machine section; opening a closed lower end of a glass tube by means of a vertical flame jet directed upwardly provided by a vertical burner nozzle stationary mounted on the stationary machine frame at an opening station; forming a tip for a needle, at the lower end of the glass tube by means of continuously rotary forming rollers horizontally and rotary mounted on the stationary machine frame at a tip forming station; and cutting off a syringe body from the glass tube having the needle tip formed at its lower end, by means of a horizontal flame jet provided by a burner nozzle horizontally mounted on the stationary machine frame, at a cutting off station; then translating the syringe body having a needle tip formed at its lower end and an upper closed end, to a second machine section intermittently rotating to a plurality of stations: continuously rotary holding each syringe body by means of rotary gripping chucks equally and stationary mounted on the stationary machine frame; translating the syringe body to a plurality of forming and finishing stations by intermittently rotating the second machine section; opening the closed upper end of the syringe body, by means of a vertical flame jet directed downward provided by a vertical burner nozzle stationary mounted on the stationary machine frame at an opening station; forming a perpendicular flat finger flange at the opened upper end of the syringe body by means of a slanting flame jet provided by a slanting burner nozzle, slanting and stationary mounted on the stationary machine frame at a finger flange forming station; fire finishing the just formed finger flange by means of a burner nozzle horizontally and stationary mounted at the stationary machine frame at a fire finishing station; and finally discharging the syringe body at a discharging station.
The above disclosed method has to be carried out in the intermittently rotary type forming machine having a tooling specifically invented to carry out this method, as disclosed in connection with the method.
In these way, the syringe body can be produced continuously from a plurality of automatically fed long glass tubes, in a single forming cycle in an intermittently and horizontally rotary type forming machine, at a high velocity of production.
It is therefore a main objective of the present invention, to provide an intermittently horizontally-rotary forming machine for the manufacturing of syringe bodies form vertically fed long glass tubes in a single continuous forming cycle.
It is also a main objective of the present invention, to provide an intermittently horizontally-rotary forming machine for the manufacturing of syringe bodies, of the above disclosed nature including two machine forming sections, a first machine section for forming a tip at a lower end of a glass tube and cutting off a syringe body therefrom, and a second machine section for forming a finger flange at an upper closed end of a just formed syringe body including the tip for a needle.
It is still a main objective of the present invention, to provide an intermittently horizontally-rotary forming machine for the manufacturing of syringe bodies, of the above disclosed nature, including a plurality of heating and softening burners and a plurality of forming mechanisms, respectively mounted on a stationary machine frame of the first and second machine sections, for forming the needle tip portion at the lower end of a glass tube, cutting off a syringe body from the glass tube and forming the finger flange at an upper end of the syringe body.
It is an additional main abject of the present invention, to provide a method for the manufacturing of syringes by vertically feeding long glass tubes to an intermittently horizontally-rotary forming machine including two forming sections.
It is also a main abject of the present invention, to provide a method for the manufacturing of syringes, of the above mentioned nature, by firstly forming a tip portion at a lower end of the glass tube, at a first machine section, cutting off a syringe body including the needle tip portion at its lower end and then opening an upper end of the syringe body and forming a finger flange at the upper end of the syringe body.
These and other objects and advantages of the present invention will be apparent to those persons having ordinary skill in the art from the following detailed description of the invention.